Aquifers

The Kuiseb Schemes

The alluvial aquifer in the lower part of the Kuiseb River at Rooibank was used since 1923 to supply water to Walvis Bay. In 1966 the Rooibank B Area was developed and in 1992 an additional wellfield at Dorop South closer to the coast came into operation. Another wellfield was established at Swartbank upstream of Rooibank in 1974 to supply Swakopmund and Rössing Mine. At the moment (2006) the Kuiseb well fields are only used for water supply to Walvisbay. In addition to 56 boreholes in the Kuiseb wellfields there is one large-diameter well (Fehlmann well). The alluvium in the Kuiseb River is 15-30 m thick. Its relatively high permeability allows high pumping rates and quick recharge in case of floods. The combined sustainable yield of the Lower Kuised Aquifers was however overestimated in the 1970s (11 Mm3/a) and the figure was revised to 7 Mm3/a in the 2000.

The Kuiseb Dune Area Investigation

The geophysical investigation of the area under the dunes south of the Kuiseb River outlined the channels created by the Kuiseb River while gradually shifting its course northward. Its mouth was previously at Sandwich Harbour where fresh water springs still occur today. The map shows the paleochannels in yellow. The area was studied as a potential water source for Walvis Bay , but the water reserves, borehole yields and water quality did not warrant the construction of a wellfield in this relatively inaccessible dune area.

 
 
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